These mutual interests of the press and of the library may seem to be of a somewhat routine, conventional character , and apart from the reviews of new books, to affect little the question
of authoritativeness with which the historian is primarily con cerned . Yet neither can afford to neglect the other and the historian is equally dependent on both . This partial enumeration of the manifold relationships of the press and other activities must indicate that it is a source for the study of any period and of presumably any question , and that therefore it can not be ignored by the historian . Yet while all of these ramifications of the newspaper must make it clear that the historian can not ignore periodical literature if the history written is to be the result of a study of the development of the
present from the past, it is this very inter-relation of the press
and all of these other activities that becomes one of his greatest perplexities in judging of the authoritativeness of the material presented. He has an absolute legal guarantee for a large part of the matter appearing in every newspaper ; he has a probable
guarantee of the reliability of the mass of material furnished by the great news-collecting agencies ; he has no effective guarantee of what is provided by the local reporter; in the large , vaguely
defined territory where other occupations and interests share
with the newspaper overlapping claims, the historian has and can have no fixed permanent guarantee of the authoritativeness
of the material presented . All of this he must test by the laws of evidence used in the examination of other classes of records, and only that part that stands the test can be accepted by him .
An effort has been made to indicate the general lines along
which these tests must be applied , and to suggest the special dangers connected with some subjects, and the comparative immunity from danger of others. But to a large extent every
individual question must be decided on its own merits and it must be decided by every individual historian who uses the news
paper as historicalmaterial.